Go down again and you will see an impressive overview of the Behemoth floor. Go north behind the stairs and find a spot to levitate down to a small platform with 2 Cyclopes, approximately here. On this platform, go to the northern edge and look north for large rocks. If there are no large rocks, you can skip the next part.

Go back south and levitate up to the platform you came from. Go east and down the staircase. Go all the way west and half way south to reach the next staircase. Go up, and follow either path to the south-eastern staircase. Go up, kill the Dragon Lord and use a Destroy Field Rune on the tile furthest west of the northern corridor row (see image). You may have to move corpses to find the lever. When the lever is to the right, backtrack to the rocks for the next step.

Go down the stairs on the platform and kill the Behemoths, Dwarf Soldiers and Cyclopes that spawn by the stairs. Go north through the narrow passage and up the stairs. Go through the level 80 Door of Expertise and prepare yourself for the final room.